JP2023094527A - Resin composition and molded article of the same - Google Patents

Abstract

To provide a resin composition which has high stress relaxation property and excellent light diffusion property inside a resin while suppressing lowering of flowability, and a molded article of the same.SOLUTION: A resin composition contains 15-99 pts.wt. of a base material resin (A) composed of at least one thermoplastic resin selected from the group consisting of a polycarbonate-based resin, a vinyl-based copolymer including a structural unit derived from an aromatic vinyl monomer and a structural unit derived from a vinyl cyanide monomer, a polyester resin, a styrenic resin, and a (meth)acrylic resin, and 0.01-20 pts.wt. of porous resin particles (B).SELECTED DRAWING: None

Description

The present invention relates to resin compositions and molded articles thereof. More specifically, the present invention improves the light diffusion and stress relaxation properties inside the resin while preventing a decrease in tensile elastic modulus and fluidity. The present invention relates to a resin composition and a molded article thereof useful as housings for electronic devices, housings for IT equipment, housings for measuring equipment, automobile interior and exterior members, and the like.

Conventionally, polycarbonate (PC) / acrylonitrile butadiene styrene (PC) / acrylonitrile butadiene styrene ( ABS) alloy, PC/polyester (polybutylene terephthalate (PBT), polyethylene terephthalate (PET) alloy), PBT, PC/polystyrene (PS) alloy, acrylic resin (PMMA), etc. Molded products are used.

In recent years, the thickness of these molded products has been reduced year by year with the aim of reducing weight and increasing functionality. etc. are required.

In addition, mainly for automobile interior parts, there is a growing trend to eliminate painting for the purpose of reducing the environmental load and reducing the total cost, and among them, there is a demand for high designability by reducing the gloss of the resin composition. The glossiness of a molded product is generally reduced by texturing, but texturing alone may not sufficiently reduce glossiness and transparency. In particular, a resin material having light diffusibility inside the resin is desired because the glossiness and transparency are conspicuous when formed into a three-dimensional curved surface shape.

Addition of a light diffusing agent to the resin composition is known as a method for imparting light diffusibility to the inside of the resin. For example, Patent Documents 1 to 3 each disclose addition of silicone particles or acrylic particles, addition of single hollow glass beads, and addition of an inorganic porous filler.

JP 2017-88892 A Japanese Patent Application Laid-Open No. 2020-117705 JP 2009-126957 A

Conventional resin compositions disclosed in Patent Documents 1 to 3 and the like require a large amount of light diffusing agent to be added in order to obtain sufficient light diffusing properties. Therefore, the fluidity of the obtained resin composition is greatly reduced, and the injection moldability is deteriorated. Moreover, the stress relaxation effect is also insufficient.

The present invention has been made to solve the above problems, and the main purpose thereof is to provide a resin composition having high stress relaxation properties and excellent light diffusion properties inside the resin while suppressing a decrease in fluidity, and It is to provide the molded product.

According to one aspect of the present invention, a polycarbonate resin, a vinyl copolymer containing a structural unit derived from an aromatic vinyl monomer and a structural unit derived from a vinyl cyanide monomer, a polyester resin, a styrene resin, and ( 15 to 99 parts by weight of base resin (A) comprising at least one thermoplastic resin selected from the group consisting of meth)acrylic resins, and 0.01 to 99 parts by weight of porous resin particles (B) 20 parts by weight of a resin composition is provided.
In one embodiment, in a tensile stress relaxation test, the stress relaxation rate R1 of the resin composition and the stress relaxation rate R0 of the base resin (A) satisfy the following formula (1).
0.3%≦R1−R0≦5.0% (1)
In the tensile stress relaxation test, a tensile force is applied to a test piece (width: 6 mm, thickness: 1 mm, test piece shape: dumbbell-shaped No. 5 described in JIS K7127), and a tensile strain of 1.5% is applied, It is a test that holds the tensile strain for 5 minutes after applying the tensile strain of 1.5%,
The stress relaxation rate R is expressed by the following formula (2):
R(%)=(σ0−σ5)/σ0×100 (2)
where σ0 represents the tensile stress of the test piece when the 1.5% tensile strain is applied to the test piece, and σ5 is the 1.5% strain on the test piece. It represents the tensile stress of the test piece 5 minutes after the tensile strain was applied.
In one embodiment, the porous resin particles (B) have a volume average particle size of 1 μm to 50 μm.
In one embodiment, the porous resin particles (B) are composed of surface porous resin particles (B1) having a porous surface and a porous interior and a nonporous surface and a porous interior. at least one selected from hollow porous resin particles (B2) having
In one embodiment, the surface porous resin particles (B1) have a specific surface area of 70 m ² /g to 300 m ² /g.
In one embodiment, the surface porous resin particles (B1) contain a polymer containing a structural unit derived from methyl methacrylate and a structural unit derived from a (meth)acrylic crosslinkable monomer, and the polymer is The content ratio of the structural unit derived from methyl methacrylate in the total amount of the structural units constituting the polymer is 1% to 50% by weight, and the (meth)acrylic crosslinkable monomer-derived structure in the total amount of the structural units constituting the polymer. The unit content is 50% to 99% by weight.
In one embodiment, the hollow porous resin particles (B2) have a specific surface area of 1 m ² /g to 30 m ² /g and a bulk specific gravity of 0.01 g/cm ³ to 0.6 g/cm ³ .
In one embodiment, the hollow porous resin particles (B2) are at least selected from the group consisting of structural units derived from vinyl monomers and structural units derived from phosphate ester monomers having ethylenically unsaturated groups. Includes polymers containing one.
In one embodiment, the resin composition contains a flame retardant, a fluidity improver, a heat stabilizer, an antioxidant, a colorant, a release agent, a softener, an antistatic agent, and an impact modifier. It further contains at least one selected from the group.
According to another aspect of the present invention, there is provided a molded article containing the above resin composition.
In one embodiment, the molded article is a vehicle equipment housing, an electrical equipment housing, an electronic equipment housing, an IT equipment housing, a measuring equipment housing, or an automobile interior/exterior member.

A resin composition according to an embodiment of the present invention contains a substrate resin (A) made of a predetermined thermoplastic resin and porous resin particles (B). Since the porous resin particles are excellent in light diffusibility, a resin composition having high light diffusivity can be obtained with a small addition amount. Moreover, due to its structure, it can impart high stress relaxation properties to the resin composition. Therefore, according to the embodiment of the present invention, it is possible to provide a resin composition having high stress relaxation properties and excellent light diffusibility inside the resin and a molded article thereof while suppressing a decrease in fluidity.

1 is a surface SEM image of surface porous resin particles (B1) produced in Production Example 1. FIG. 1 is a cross-sectional SEM image of a surface porous resin particle (B1) produced in Production Example 1. FIG. 4 is a surface SEM image of hollow porous resin particles (B2) produced in Production Example 2. FIG. 4 is a cross-sectional SEM image of hollow porous resin particles (B2) produced in Production Example 2. FIG.

Embodiments of the present invention will be described below, but the present invention is not limited to these embodiments. In this specification, when the expression "(meth)acrylic" is used, it means "acrylic and/or methacrylic", and when the expression "(meth)acrylate" is used, "acrylate and/or or methacrylate", and the expression "(meth)allyl" means "allyl and/or methallyl", and the expression "(meth)acrolein" means "acrolein and/or or methacrolein". Moreover, when there is an expression of "acid (salt)" in this specification, it means "acid and/or its salt." Examples of salts include alkali metal salts and alkaline earth metal salts, and specific examples include sodium salts and potassium salts. Further, in this specification, the term "weight" is synonymous with "mass" in the SI unit system, which means weight.

<<Resin composition>>
The resin composition according to an embodiment of the present invention includes a polycarbonate resin, a vinyl copolymer containing a structural unit derived from an aromatic vinyl monomer and a structural unit derived from a vinyl cyanide monomer, a polyester resin, a styrene resin, and 15 to 99 parts by weight of a base resin (A) comprising at least one thermoplastic resin selected from the group consisting of (meth)acrylic resins, and 0.01 parts by weight of porous resin particles (B) ~20 parts by weight. The resin composition of the present embodiment may further contain any appropriate other component depending on the purpose.

The melt volume flow rate (MVR) of the resin composition measured at 250° C. and 2.16 kgf is, for example, 2.5 cm ³ /10 min to 40 ^{cm 3} /10 min, preferably 3 cm ³ /10 min to 30 cm ³ /10 min. Yes, more preferably 3 cm ³ /10 min to 20 cm ³ /10 min. If the MVR is within the above range, the balance between fluidity and retention is good during injection molding, and moldability is improved.

The difference (R1-R0) between the stress relaxation rate R1 of the molded piece (thickness 1 mm) of the resin composition and the stress relaxation rate R0 of the molded piece (thickness 1 mm) of the base resin (A) is preferably 0.5. It is 3% or more, more preferably 0.5% or more. Although the upper limit of the difference is not particularly limited, it may be, for example, 5.0% or less, preferably 3.0% or less. Thus, the resin composition according to the embodiment of the present invention can have improved stress relaxation properties compared to the base resin (A) due to the inclusion of the porous resin particles (B). The stress relaxation rate can be measured by the tensile stress relaxation test described in Examples.

A molded piece (thickness: 1 mm) of the resin composition preferably has a total light transmittance of 80% or less, more preferably 70% or less, and still more preferably 60% or less. Although the lower limit of the total light transmittance is not particularly limited, it is preferably 5% or more, more preferably 10% or more. If the total light transmittance is within the above range, it is preferable because the range of use as a member of the molded article is not limited.

The haze of a molded piece (thickness 1 mm) of the resin composition is preferably 70% or more, more preferably 80% or more, still more preferably 85% or more. The upper limit of the total light transmittance is not particularly limited. If the haze is within the above range, it is preferable because the range of use as a member of the molded article is not limited.

A. Base resin (A)
The content of the base resin (A) in the resin composition is typically 15 parts by weight to 99 parts by weight, preferably 30 parts by weight to 99 parts by weight, based on 100 parts by weight of the resin composition. It is preferably 50 to 99 parts by weight, more preferably 70 to 99 parts by weight. If the content of the base resin (A) is within the above range, both molding workability and strength can be achieved.

The base resin (A) includes a polycarbonate resin, a vinyl copolymer containing a structural unit derived from an aromatic vinyl monomer and a structural unit derived from a vinyl cyanide monomer, a polyester resin, a styrene resin, and (meth) It is composed of one or more thermoplastic resins selected from the group consisting of acrylic resins. The base resin (A) composed of two or more thermoplastic resins is obtained by mixing (e.g., compatible, dispersing) and/or secondary block polymerization or graft polymerization of two or more thermoplastic resins. It may be a polymer alloy (polymer multicomponent system) obtained by The blending ratio of each resin in the polymer alloy is not limited as long as the effects of the present invention can be obtained.

The base resin (A) has a softening temperature of preferably 75° C. or higher, more preferably 90° C. or higher, and for example 200° C. or lower. If the softening point is within the above range, the heat resistance of the base resin (A) can be improved. The softening point can be measured, for example, according to the Vicat softening point specified in JIS K7206-1999.

The base resin (A) preferably has a tensile modulus of 1.0 GPa or more, more preferably 2.0 GPa or more, and for example 4.0 GPa or less. If the tensile modulus is within the above range, the strength of the base resin (A) can be improved. The tensile modulus can be measured, for example, according to the tensile modulus specified in JIS K7161-2014.

The base resin (A) preferably contains a polycarbonate-based resin. The content of the polycarbonate-based resin in the base resin (A) is preferably 1 to 100 parts by weight, more preferably 10 to 90 parts by weight, still more preferably 100 parts by weight of the base resin (A). can be from 20 parts by weight to 80 parts by weight.

When the base resin (A) is composed of two or more thermoplastic resins, the thermoplastic resin preferably contains a polymer alloy, more preferably a polymer alloy containing a polycarbonate resin. The content of the polymer alloy in the base resin (A) is, for example, 1 to 100 parts by weight, preferably 1 to 99 parts by weight, more preferably 1 to 99 parts by weight, based on 100 parts by weight of the base resin (A). It may be 20 to 70 parts by weight, more preferably 30 to 60 parts by weight. Preferred polymer alloys include PC/ABS alloy resin, PC/PET alloy resin, PC/PBT alloy resin, and the like.

A-1. Polycarbonate-based resin As the polycarbonate-based resin, for example, an aromatic polycarbonate obtained by reacting a dihydric phenol and a carbonate precursor can be used. Specific examples thereof include aromatic polycarbonates obtained by an interfacial polymerization method (solution method) in which dihydric phenol and phosgene are reacted or an ester exchange method (melt method) between dihydric phenol and diphenyl carbonate or the like. Each of the dihydric phenol and the carbonate precursor may be of only one type, or may be of two or more types.

Examples of dihydric phenol include 2,2-bis(4-hydroxyphenyl)propane [bisphenol A], bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, 2,2 - Bis(hydroxyphenyl)alkane compounds such as bis(4-hydroxy-3,5-dimethylphenyl)propane; 4,4'-dihydroxydiphenyl, bis(4-hydroxyphenyl)cycloalkane, bis(4-hydroxyphenyl) ) oxide, bis(4-hydroxyphenyl) sulfide, bis(4-hydroxyphenyl) sulfone, bis(4-hydroxyphenyl) sulfoxide, bis(4-hydroxyphenyl) ether and bis(4-hydroxyphenyl) ketone, or Halogen-substituted products thereof and the like are included. Of these, bis(hydroxyphenyl)alkane compounds, particularly bisphenol A, are preferred. In addition, dihydric phenols include hydroquinone, resorcinol, catechol and the like.

Carbonate precursors include carbonyl halides, carbonyl esters, haloformates, and the like. More specifically, phosgene, dihaloformate of dihydric phenol, diphenyl carbonate, dimethyl carbonate, diethyl carbonate and the like.

The polycarbonate-based resin may have a branched structure. Branching agents used to introduce a branched structure include 1,1,1-tris(4-hydroxyphenyl)ethane, α,α',α″-tris(4-hydroxyphenyl)-1,3,5 -triisopropylbenzene, phloroglucine, trimellitic acid, isatin bis(o-cresol), etc. Also, for molecular weight control, phenol, pt-butylphenol, pt-octylphenol, p-cumylphenol etc. can be used as a terminal terminator.

The viscosity-average molecular weight of the polycarbonate-based resin is preferably 10,000 to 100,000, more preferably 14,000 to 40,000, from the viewpoint of mechanical strength and moldability.

The polycarbonate-based resin may be a copolymer having a polycarbonate portion and a polyorganosiloxane portion, or a polycarbonate-based resin containing this copolymer. It may also be a polyester-polycarbonate resin obtained by polymerizing a polycarbonate in the presence of a bifunctional carboxylic acid such as terephthalic acid or an ester precursor such as an ester-forming derivative thereof. As the polycarbonate-based resin, one type may be used alone, or two or more types having different constitutional unit types, compositions, physical properties, and the like may be used.

A-2. Vinyl-Based Copolymer The vinyl-based copolymer contains at least a structural unit derived from an aromatic vinyl monomer and a structural unit derived from a vinyl cyanide monomer. The vinyl-based copolymer may contain, in addition to the structural units derived from the aromatic vinyl monomer and the structural units derived from the vinyl cyanide monomer, structural units derived from other vinyl monomers copolymerizable therewith.

Examples of aromatic vinyl monomers include styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, ethylstyrene, vinyltoluene, vinylxylene, methyl-α-methylstyrene, t-butylstyrene, divinylbenzene, Chlorinated styrenes such as 1,1-diphenylstyrene, N,N-diethyl-p-aminomethylstyrene, N,N-diethyl-p-aminoethylstyrene, vinylnaphthalene, vinylpyridine, monochlorostyrene, dichlorostyrene; monobromo brominated styrene such as styrene and dibromostyrene; monofluorostyrene; Of these, styrene and α-methylstyrene are preferred. These aromatic vinyl monomers may be used alone or in combination of two or more.

Vinyl cyanide monomers include, for example, acrylonitrile, methacrylonitrile, ethacrylonitrile, fumaronitrile, and the like. Among them, acrylonitrile is preferred. Only one kind of these vinyl cyanide monomers may be used, or two or more kinds thereof may be used.

Examples of other vinyl monomers include acrylic acid esters (methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, etc.), methacrylic acid esters (methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, etc.), maleimide compounds (N-cyclohexylmaleimide, N-phenylmaleimide, etc.), and the like. Other vinyl monomers may be used alone or in combination of two or more.

The content of the structural unit derived from the aromatic vinyl monomer in 100 parts by weight of the vinyl copolymer is preferably 50 parts by weight to 90 parts by weight, more preferably 55 parts by weight to 80 parts by weight, and still more preferably. is 60 to 70 parts by weight. If the content of the structural unit derived from the aromatic vinyl monomer is within the above range, the resulting molded article will have good warpage characteristics.

The content of the structural unit derived from the vinyl cyanide monomer in 100 parts by weight of the vinyl copolymer is preferably 10 parts by weight to 50 parts by weight, more preferably 20 parts by weight to 45 parts by weight, even more preferably. is 30 to 40 parts by weight. If the content of the structural unit derived from the vinyl cyanide monomer is within the above range, the resulting molded article will have good warpage properties.

The content of structural units derived from other vinyl monomers in 100 parts by weight of the vinyl copolymer is preferably 0 to 30 parts by weight.

The weight average molecular weight (Mw) of the vinyl copolymer is preferably 50,000 to 300,000, more preferably 60,000 to 250,000. When the weight average molecular weight (Mw) of the vinyl copolymer is within the above range, the obtained resin composition tends to have good fluidity and impact resistance.

As the vinyl-based copolymer, one type may be used alone, or two or more types having different constitutional unit types, compositions, physical properties, and the like may be used.

A-3. Polyester-based resin Examples of polyester-based resins include polymers or copolymers obtained by a polycondensation reaction containing a dicarboxylic acid (or its ester-forming derivative) and a diol (or its ester-forming derivative) as main components. can be used. Each of the dicarboxylic acid and the diol may be used alone or in combination of two or more.

Dicarboxylic acids include terephthalic acid, isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,2′-biphenyldicarboxylic acid, 3,3 '-biphenyldicarboxylic acid, 4,4'-biphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, 4,4'-diphenylmethanedicarboxylic acid, 4,4'-diphenylsulfonedicarboxylic acid, 4,4'-diphenylisopropyl redenedicarboxylic acid, 1,2-bis(phenoxy)ethane-4,4'-dicarboxylic acid, 2,5-anthracenedicarboxylic acid, 2,6-anthracenedicarboxylic acid, 4,4'-p-terphenylenedicarboxylic acid, Aromatic dicarboxylic acids such as 2,5-pyridinedicarboxylic acid can be mentioned. Among these, terephthalic acid is preferred.

In a small amount, one or more of aliphatic dicarboxylic acids such as adipic acid, azelaic acid, dodecanedioic acid and sebacic acid, and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid can be used together with the aromatic dicarboxylic acid. .

Diols include aliphatic diols such as ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, neopentyl glycol, 2-methyl-1,3-propanediol, diethylene glycol and triethylene glycol, and 1,4-cyclohexanedimethanol. alicyclic diols such as and mixtures thereof. Among these, ethylene glycol, propylene glycol and butylene glycol are preferred.

In small amounts, one or more long-chain diols having a molecular weight of 400 to 6,000, such as polyethylene glycol, poly-1,3-propylene glycol, and polytetramethylene glycol, can be used together with the above diols.

Specific examples of polyester resins include polyethylene terephthalate (PET), polypropylene terephthalate (PPT), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polybutylene naphthalate (PBN), polyethylene-1,2-bis Aromatic polyester resins such as (phenoxy)ethane-4,4′-dicarboxylate and copolymer aromatic polyester resins such as polybutylene terephthalate/isophthalate and polybutylene terephthalate/decanedicarboxylate are exemplified. Among these, PET and PBT are preferable from the viewpoint of ease of workability and mechanical properties.

As the polyester-based resin, one type may be used alone, or two or more types having different constitutional unit types, compositions, physical properties, and the like may be used. The polyester resin may be, for example, a mixture of PET and PBT.

A-4. Styrene-based resins Styrene-based resins include rubber-modified styrene polymers obtained by dissolving rubber components in styrene-based monomers and polymerizing them by known polymerization methods such as bulk polymerization and suspension polymerization, and styrene-based monomers and rubbers. components are physically mixed by a known method to form a mixture of a styrenic monomer and a rubber component.

Styrenic monomers include, for example, styrene, α-methylstyrene, α-methyl-p-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, ethylstyrene, p -t-butylstyrene, 1,1-diphenylethylene, bromostyrene, dibromostyrene, chlorostyrene, dichlorostyrene and the like. Only one type of styrene-based monomer may be used, or two or more types may be used. When two or more types of styrene-based monomers are used, it is preferable to contain 50 parts by weight or more of styrene with respect to 100 parts by weight of the styrene-based monomer.

Examples of rubber components include polybutadiene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, polyisoprene, styrene-isoprene copolymer, butadiene-methacrylate copolymer, acrylic rubber, and ethylene-propylene. rubber, ethylene-propylene-diene rubber, hydrogenated diene rubber, and the like. Only one rubber component may be used, or two or more rubber components may be used. When using two or more rubber components, the mixing ratio is not particularly limited.

Examples of rubber-modified styrene polymers include so-called high impact polystyrene (HIPS) and acrylonitrile-butadiene-styrene copolymer (ABS).

A-5. Meta(acrylic)-based resin As the meta(acrylic)-based resin, a methyl methacrylate-based resin is preferable. Specifically, the meth(acrylic) resin may contain preferably 80 mol % or more, more preferably 90 mol % or more of structural units derived from methyl methacrylate based on the total amount of structural units. Meta (acrylic) resins, which are copolymers of methyl methacrylate and acrylic acid alkyl esters such as methyl acrylate, ethyl acrylate and butyl acrylate, can also be preferably used.

The weight average molecular weight of the meta (acrylic) resin is preferably 20,000 to 200,000, more preferably 50,000 to 150,000. The weight average molecular weight is a value measured by gel permeation chromatography using standard polystyrene as a standard sample.

Methods for producing the meth (acrylic) resin include, for example, an emulsion polymerization method, a suspension polymerization method, and a continuous polymerization method. A continuous polymerization method is preferred, and either a continuous bulk polymerization method or a continuous solution polymerization method may be used.

Only one type of meta (acrylic) resin may be used, or two or more types may be used.

B. Porous resin particles (B)
The porous resin particles (B) are resin particles having a porous structure at least partially, preferably resin particles having a porous structure inside the particles. The porous resin particles (B) can impart high stress relaxation properties to the resin composition due to their structure and forming materials. In addition, since it has excellent light diffusibility, it is possible to impart sufficient light diffusivity to the resin composition with a small amount of addition, and as a result, avoids a significant decrease in fluidity or mechanical strength of the resin composition. obtain.

The porous resin particles (B) may have any appropriate structure as long as the effects of the present invention are obtained. Specific examples of the porous resin particles (B) include surface porous resin particles (B1) having a porous surface and a porous interior, and hollow porous resin particles having a nonporous surface and a porous interior. quality resin particles (B2). The pores of the porous structure are typically filled with a substance other than resin, such as gas or liquid. It is The specific surface area of the porous resin particles (B) can be, for example, 1 m ² /g to 300 m ² /g.

The volume average particle diameter of the porous resin particles (B) is preferably 1 μm to 50 μm, more preferably 2 μm to 40 μm, still more preferably 3 μm to 30 μm. If the volume average particle size is within the above range, high internal light diffusibility can be imparted while suppressing warpage of the molded product due to the stress relaxation effect.

The thermal decomposition initiation temperature of the porous resin particles (B) is preferably 250° C. or higher, more preferably 280° C. or higher. The upper limit of the thermal decomposition initiation temperature may be 420° C., for example. If the thermal decomposition initiation temperature is within the above range, thermal decomposition due to heating during kneading with the base resin is suppressed, and the porous shape can be maintained.

The content of the porous resin particles (B) in the resin composition is typically 0.01 to 20 parts by weight, preferably 0.1 to 15 parts by weight, per 100 parts by weight of the resin composition. parts by weight, more preferably 0.5 to 10 parts by weight, still more preferably 1 to 5 parts by weight. The content of the porous resin particles (B) in the resin composition is 0.1 to 15 parts by weight, more preferably 0.5 parts by weight, per 100 parts by weight of the base resin (A). It is from 1 to 10 parts by weight, more preferably from 1 to 5 parts by weight. If the content of the porous resin particles (B) is within the above range, high internal light diffusibility can be imparted while maintaining the impact strength.

B-1. Surface porous resin particles (B1)
A surface porous resin particle has a porous structure not only on the particle surface but also on the inside thereof. That is, the surface porous resin particles have a porous structure as a whole.

The specific surface area of the superficially porous resin particles is, for example, 70 m ² /g to 300 m ² /g, preferably 75 m ² /g to 280 m ² /g, more preferably 80 m ² /g to 250 m ² /g. is g. If the specific surface area is within the above range, high internal light diffusibility can be imparted while maintaining particle strength to the extent that the shear force during kneading does not break the particles.

The pore volume of the superficially porous resin particles is preferably 0.1 ml/g to 1.0 ml/g, and the average pore diameter is preferably 2 nm to 50 nm. If the pore volume is less than 0.1 ml/g and the average pore diameter is less than 2 nm, a sufficient stress relaxation effect may not be obtained. Further, when the pore volume exceeds 1.0 ml/g and the average pore diameter exceeds 50 nm, it may not be possible to obtain particle strength to the extent that the shear force during kneading does not break the particles. The pore volume refers to the pore volume per unit weight, and in this specification means the pore volume obtained from the nitrogen desorption isotherm using the BJH method. Moreover, the average pore diameter means the average pore diameter obtained based on the BJH method from the nitrogen desorption isotherm.

The surface porous resin particles typically contain a polymer (P1) containing structural units derived from methyl methacrylate and structural units derived from a (meth)acrylic crosslinkable monomer. The polymer (P1) is a polymer of monomer components containing at least methyl methacrylate and a (meth)acrylic crosslinkable monomer. The polymer (P1) may contain structural units derived from monomers other than methyl methacrylate and (meth)acrylic crosslinkable monomers, if necessary. In addition, the weight ratio of each monomer in all monomer components constituting the polymer (P) (hereinafter sometimes simply referred to as "monomer components"), and the total amount of structural units constituting the polymer (P1) derived from each monomer is substantially the same as the weight ratio of the constituent units of

The content of the polymer (P1) in the surface porous resin particles is typically 50% to 100% by weight, preferably 70% to 100% by weight, more preferably 90% by weight. % to 100% by weight, more preferably 95% to 100% by weight, particularly preferably 98% to 100% by weight.

The structural unit derived from methyl methacrylate is a structural unit formed when methyl methacrylate is polymerized as one of all monomer components used for producing the polymer (P1). The content of methyl methacrylate in the monomer component is typically 1% to 50% by weight, preferably 10% to 50% by weight. If the content ratio is within the above range, the (meth)acrylic crosslinkable monomer can be sufficiently contained in the monomer component. It is possible to obtain superficially porous resin particles that can be made larger and have sufficient heat resistance and strength.

The structural unit derived from the (meth)acrylic crosslinkable monomer is formed when the (meth)acrylic crosslinkable monomer is polymerized as one of all the monomer components used to produce the polymer (P1). It is a structural unit that As such a (meth)acrylic crosslinkable monomer, any suitable (meth)acrylic monomer having two or more ethylenically unsaturated groups can be employed as long as the effects of the present invention are not impaired. The number of (meth)acrylic crosslinkable monomers may be one, or two or more.

Examples of (meth)acrylic crosslinkable monomers include ethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, allyl (meth)acrylate, trimethylolpropane tri(meth)acrylate, and pentaerythritol. Tetra (meth) acrylate etc. are mentioned. Among these, ethylene glycol di(meth)acrylate is particularly excellent in the effect of improving the heat resistance of the surface porous resin particles.

The content of the (meth)acrylic crosslinkable monomer in the monomer component is typically 50% to 99% by weight, preferably 50% to 90% by weight. If the content is within the above range, the superficially porous resin can impart sufficient porosity to the superficially porous resin particles, can increase the specific surface area, and has sufficient heat resistance and strength. particles can be obtained.

The surface porous resin particles may contain an antioxidant for the purpose of further improving heat resistance. Any suitable antioxidant can be used, and specific examples thereof include 2,6-di-t-butyl-4-methylphenol, n-octadecyl-3-(3′, 5′-di-t-butyl-4′-hydroxyphenyl)propionate, tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyloxymethyl]methane, tris[N-(3, 5-di-t-butyl-4-hydroxybenzyl)]isocyanurate, butylidene-1,1-bis(2-methyl-4-hydroxy-5-t-butylphenyl), triethylene glycol bis[3-(3 -t-butyl-4-hydroxy-5-methylphenyl)propionate], 3,9-bis{2-[3(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1 -dimethylethyl}-2,4,8,10-tetraoxaspiro[5.5]undecane and other phenolic antioxidants; dilauryl-3,3'-thio-dipropionate, dimyristyl-3,3'-thio- Dipropionate, distearyl-3,3'-thio-dipropionate, pentaerythritol tetrakis(3-laurylthio-propionate), pentaerythritol tetrakisthioglycolate, pentaerythritol thiopropionate, pentaerythritol tetrakis(4-butanate), pentaerythritol Tetrakis(6-mercaptohexanate), trimethylolpropane tristhioglycolate, trimethylolpropane tristhiopropionate, trimethylolpropane tristhiobutanate, butanediol bisthioglycolate, ethylene glycol bisthioglycolate, hexanediol Sulfur-based antioxidants such as bisthioglycolate, butanediol bisthiopropionate, ethylene glycol bisthiopropionate, octyl thioglycolate, 1-octanethiol, 1-dodecanethiol, thiosalicylic acid; tris(nonylphenyl ) phosphite, tris(2,4-di-t-butylphenyl) phosphite, distearylpentaerythritol diphosphite, bis(2,4-di-t-butylphenyl)pentaerythritol phosphite, 2,2- Phosphorus-based antioxidants such as methylenebis(4,6-di-t-butylphenyl)-4,4'-biphenylenedi-phosphonite and the like are included. Only one kind of antioxidant may be used, or two or more kinds thereof may be used.

The content of the antioxidant is preferably 0.01 to 5 parts by weight, more preferably 0.1 to 1 part by weight, per 100 parts by weight of the monomer component. If the content of the antioxidant is less than the above range, the effect of improving the heat resistance due to the inclusion of the antioxidant may not be obtained, and if the content of the antioxidant exceeds the above range, oxidation There is a possibility that the effect of improving the heat resistance corresponding to the content of the inhibitor may not be obtained, which is uneconomical in terms of cost.

The amount of unreacted methyl methacrylate remaining in the superficially porous resin particles is 20 ppm or less. When the amount of unreacted methyl methacrylate remaining in the surface porous resin particles exceeds 20 ppm, the base resin (A) discolors (yellowing) when the resin composition is extruded, resulting in poor molding. Failure to do so may result in defects.

The superficially porous resin particles can be produced, for example, by a production method including a polymerization process, a distillation process, and a drying process. The method for producing superficially porous resin particles may optionally further include a decomposition removal step between the distillation step and the drying step.

[Polymerization step]
In the polymerization step, a monomer component is suspended-polymerized in an aqueous medium in the presence of a non-polymerizable organic compound, a polymerization initiator, and an inorganic dispersant to obtain a suspension containing surface-porous resin particles ( slurry) is obtained. Suspension polymerization is, for example, droplets of an organic mixed solution (oil phase) containing a monomer component, a non-polymerizable organic compound, and a polymerization initiator in an aqueous solution (aqueous phase) containing an aqueous medium and an inorganic dispersant. can be carried out by dispersing and polymerizing the monomer components. By using an inorganic dispersant as the dispersant, coloring (yellowing) when mixed with the base resin (A) can be suppressed.

Any appropriate dispersing method may be employed for dispersing the organic mixed solution in the aqueous solution, as long as the organic mixed solution can be present in the form of droplets in the aqueous solution, as long as the effects of the present invention are not impaired. obtain. Such a dispersion method is typically a dispersion method using a homomixer or a homogenizer.

Examples of aqueous media include water and mixed media of water and water-soluble organic media (lower alcohols (alcohols having 5 or less carbon atoms) such as methanol and ethanol). The amount of the aqueous medium to be used is usually in the range of 100 parts by weight to 1000 parts by weight with respect to 100 parts by weight of the monomer component, in order to stabilize the surface porous resin particles.

Examples of inorganic dispersants that can be used include sparingly water-soluble inorganic salts such as calcium carbonate, tribasic calcium phosphate, calcium pyrophosphate, magnesium hydroxide, magnesium pyrophosphate, and colloidal silica. Among these, if one that is decomposed by an acid and dissolved in water (for example, calcium carbonate, tribasic calcium phosphate, magnesium hydroxide, magnesium pyrophosphate, calcium pyrophosphate) is used, the inorganic dispersant can be easily removed after the polymerization step. can be removed. Only one kind of inorganic dispersant may be used, or two or more kinds thereof may be used.

The amount of the inorganic dispersant added is preferably 0.1 to 20 parts by weight, more preferably 0.5 to 10 parts by weight, per 100 parts by weight of the monomer component. If the amount of the inorganic dispersant added exceeds 20 parts by weight, the viscosity of the suspension (reaction liquid) may become too high and the suspension may not flow. If the amount of the inorganic dispersant to be added is less than 0.1 parts by weight, the surface porous resin particles cannot be satisfactorily dispersed, and the particles may coalesce.

The monomer components are as described above.

The non-polymerizable organic compound is not particularly limited as long as it functions as a porosity agent, but one having high miscibility with the monomer component and low water solubility is preferably used. Specific examples of non-polymerizable organic compounds include aromatic compounds such as toluene and benzene; ester compounds such as ethyl acetate and butyl acetate; saturated aliphatic hydrocarbons such as n-heptane, n-hexane and n-octane. can be mentioned. Among these, those having a boiling point of 69°C to 90°C, for example, organic solvents having a boiling point of 69°C to 90°C such as benzene (boiling point 80°C), n-hexane (69°C), and ethyl acetate (77°C) is used, the suspension in the polymerization step can be stably performed, and the non-polymerizable organic compound can be easily removed by distillation in the distillation step. Only one kind of non-polymerizable organic compound may be used, or two or more kinds thereof may be used.

The amount of the non-polymerizable organic compound added is preferably 10 to 250 parts by weight, more preferably 50 to 220 parts by weight, per 100 parts by weight of the monomer component. If the amount added is outside the above range, it may not be possible to obtain superficially porous resin particles having the desired specific surface area and pore volume.

As the polymerization initiator, any appropriate polymerization initiator can be employed as long as the effects of the present invention are not impaired.

The polymerization initiator preferably has a 10-hour half-life temperature of 90° C. or less. By using such a polymerization initiator, the polymerization initiator remaining in the surface porous resin particles can be completely decomposed.

The polymerization initiator is preferably polymerized at a combination of reaction temperature and reaction time at which the decomposition rate of the polymerization initiator calculated by the following formula is 98% or more. Under such polymerization conditions, the polymerization initiator remaining in the surface porous resin particles can be completely decomposed.

Degradation rate (%) = (1-exp (-k _d t)) x 100
kd = A exp (-ΔE/RT)

In the above formula, k _d represents the thermal decomposition rate constant, t represents the reaction time (hr), A represents the frequency factor (hr ⁻¹ ), ΔE represents the activation energy (J / mol), R represents the gas constant (8.314 J/mol·K) and T represents the reaction temperature (K).

Examples of polymerization initiators include lauroyl peroxide, benzoyl peroxide, ortho-chlorobenzoyl peroxide, ortho-methoxy benzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, t-butylperoxy-2-ethylhexano Organic peroxides such as ate and di-t-butyl peroxide; dimethylvaleronitrile), 2,2′-azobis(2-methylbutyronitrile) and other azo compounds; Only one polymerization initiator may be used, or two or more polymerization initiators may be used.

The amount of the polymerization initiator to be added is preferably 0.01 to 10 parts by weight, more preferably 0.01 to 5 parts by weight, per 100 parts by weight of the monomer component. If the amount of polymerization initiator added is less than 0.01 parts by weight, the polymerization initiator may not function to initiate polymerization. Moreover, if the amount of the polymerization initiator added exceeds 10 parts by weight, it is uneconomical in terms of cost.

When producing porous resin particles containing an antioxidant, the suspension polymerization is carried out in the presence of the antioxidant. For example, an antioxidant is further added to an organic mixed solution (oil phase) containing a monomer component, a non-polymerizable organic compound, and a polymerization initiator to carry out suspension polymerization.

Suspension polymerization may be carried out in the presence of a surfactant in order to further stabilize the suspension (reaction solution). Surfactants can be added in the organic mixed solution (oil phase) or in the aqueous solution (water phase).

Examples of surfactants include anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants.

Examples of anionic surfactants include alkyl sulfates, alkylbenzenesulfonates, alkylnaphthalenesulfonates, alkanesulfonates, alkyldiphenylethersulfonates, dialkylsulfosuccinates, monoalkylsulfosuccinates, polyoxy Non-reactive anionic surfactants such as ethylene alkylphenyl ether phosphate, polyoxyethylene-1-(allyloxymethyl) alkyl ether sulfate ammonium salt, polyoxyethylene alkyl propenylphenyl ether sulfate ammonium salt, poly Examples thereof include reactive anionic surfactants such as oxyalkylene alkenyl ether ammonium sulfate.

Examples of cationic surfactants include cationic surfactants such as alkyltrimethylammonium salts, alkyltriethylammonium salts, dialkyldimethylammonium salts, dialkyldiethylammonium salts, and N-polyoxyalkylene-N,N,N-trialkylammonium salts. Surfactants and the like are included.

Examples of amphoteric surfactants include lauryldimethylamine oxide, phosphate ester salts, phosphite surfactants, and the like.

Examples of nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene fatty acid esters, sorbitan fatty acid esters, polysorbitan fatty acid esters, polyoxyethylene alkylamines, glycerin fatty acid esters, oxyethylene - Oxypropylene block polymers and the like.

The amount of the surfactant to be added is preferably 0.01 to 1 part by weight with respect to 100 parts by weight of the organic mixed solution. Only one type of surfactant may be used, or two or more types may be used.

The polymerization temperature is preferably from 40° C. (the boiling point of the non-polymerizable organic compound, T° C.-5° C.). The polymerization time is preferably 0.1 hour to 20 hours.

After the polymerization is completed, a suspension (slurry) containing superficially porous resin particles containing the non-polymerizable organic compound in the particles is obtained. In addition, the non-polymerizable organic compound contained in this suspension is removed by the distillation process described later.

[Distillation process]
The distillation step is a step of removing a non-polymerizable organic compound from the suspension containing the surface porous resin particles obtained in the polymerization step by distilling the suspension.

Distillation is carried out, for example, by charging a suspension containing superficially porous resin particles into a distiller and stirring it at a temperature and pressure at which at least the non-polymerizable organic compound can be distilled. At this time, it is preferable to carry out distillation at the same time as charging into the distiller. For this reason, the suspension is supplied to a distiller preliminarily adjusted to a temperature and/or pressure at which the non-polymerizable organic compound can be distilled off under reduced pressure, using a liquid feed pump or the like or by a negative pressure in the distiller. You may At this time, the suspension is continuously fed while adjusting the amount of the suspension to be supplied so that the amount of the non-polymerizable organic compound contained in the suspension to be supplied and the amount of the distillate obtained by distillation are in equilibrium. may be fed to the still. Alternatively, the suspension may be intermittently fed to the distiller with continuous feeding and feeding stoppages.

Distillation conditions vary depending on the type of non-polymerizable organic compound, but it is usually preferred to perform distillation at a temperature equal to or higher than the boiling point of the non-polymerizable organic compound under reduced pressure of 0.030 MPa or less.

Such a distillation step removes non-polymerizable organic compounds from the suspension. At the same time, the polymerization initiator contained in the suspension, the residue of this polymerization initiator, and the unreacted monomers remaining in the suspension (specifically, methyl methacrylate and (meth) acrylic cross-linking monomers) can be removed.

[Decomposition removal step]
The decomposition and removal step is a step of decomposing and removing the inorganic dispersant contained in the suspension. For example, when an inorganic dispersant that is decomposed by an acid and dissolved in water is used, the decomposition and removal step includes adding an acid to the suspension from which the non-polymerizable organic compound has been removed in the distillation step to remove the inorganic dispersant. decomposing and dissolving in a suspension; filtering the suspension to separate the superficially porous resin particles; and washing the filtered superficially porous resin particles with water. can.

By such a decomposition and removal step, the amount of residual metal derived from the inorganic dispersant contained in the resulting surface porous resin particles is reduced. Specifically, the amount of residual metal derived from the inorganic dispersant is reduced. It can be suppressed to 100 ppm or less. When superficially porous resin particles with a small amount of residual metal remaining are mixed with the base resin (A) and extruded, molding defects such as discoloration (yellowing) of the base resin (A) are less likely to occur.

[Drying process]
The drying step is a step of drying the surface porous resin particles separated from the suspension by filtration after the distillation step.

Drying may be carried out under reduced pressure of preferably 0.015 MPa or less, more preferably 0.010 MPa or less. The drying temperature is preferably 80°C or higher, more preferably 90°C or higher. The drying time is preferably 12 hours or longer, more preferably 15 hours or longer.

By such a drying process, the polymerization initiator contained in the surface porous resin particles, the residue of this polymerization initiator, and the monomer remaining in the surface porous resin particles (specifically, methyl methacrylate) are removed. and (meth)acrylic crosslinkable monomers) are further reduced. Specifically, the amount of the polymerization initiator remaining in the superficially porous resin particles and the amount of this polymerization initiator residue can be reduced to 50 ppm or less. Also, the amount of unreacted methyl methacrylate remaining in the superficially porous resin particles can be reduced to 20 ppm or less.

B-2. Hollow porous resin particles (B2)
Hollow porous resin particles typically have a dense surface (non-porous layer) and an interior (hollow portion) having a porous structure therein.

The specific surface area of the hollow porous resin particles is preferably 1 m ² /g to 30 m 2 /g, more preferably 1 m ² /g to 25 ^{m 2 /} g, still more preferably 1 m ² /g to 20 m ^{2 .} /g, particularly preferably 1 m ² /g to 15 m ² /g. If the specific surface area is within the above range, it is possible to obtain particle strength to the extent that the shear force during kneading does not break the particles.

The bulk specific gravity of the hollow porous resin particles is preferably ^0.01 g/cm ³ to 0.6 g/cm 3 , more preferably 0.02 g/cm ³ to 0.55 g/cm ³ , still more preferably. is 0.03 g/cm ³ to 0.5 g/cm ³ , particularly preferably 0.05 g/cm ³ to 0.45 g/cm ³ . If the bulk specific gravity is within the above range, the particles have a porous structure inside, and high internal light diffusibility can be imparted to the resin composition.

The hollow porous resin particles are preferably a polymer (P2 )including.

Typically, the main component of the hollow porous resin particles is at least one selected from the group consisting of structural units (I) derived from vinyl monomers and structural units (II) derived from phosphoric acid ester monomers. Polymer (P2) containing seeds. Here, the "main component" is preferably 50% by weight or more, more preferably 70% by weight or more, still more preferably 90% by weight or more, particularly preferably 95% by weight or more, and most preferably 95% by weight or more. means 98% by weight or more.

The content of the polymer (P2) in the hollow porous resin particles is preferably 50% by weight to 100% by weight, more preferably 70% by weight to 100% by weight, and still more preferably 90% by weight. ∼100% by weight, particularly preferably 95% to 100% by weight, most preferably 98% to 100% by weight.

The polymer (P2) is preferably a polymer containing both the structural unit (I) derived from the vinyl-based monomer and the structural unit (II) derived from the phosphate ester-based monomer.

The vinyl-based monomer-derived structural unit (I) is a structural unit formed when the vinyl-based monomer is polymerized as one of all the monomer components used for producing the polymer (P2). As such a vinyl-based monomer, any appropriate vinyl-based monomer can be employed as long as the effects of the present invention are not impaired. Only one kind of vinyl-based monomer may be used, or two or more kinds thereof may be used.

Examples of vinyl-based monomers include monofunctional vinyl-based monomers having one ethylenically unsaturated group and polyfunctional vinyl-based monomers having two or more ethylenically unsaturated groups.

Examples of monofunctional vinyl monomers having one ethylenically unsaturated group include styrene monomers, carboxyl group-containing monomers, (meth)acrylic acid alkyl esters, hydroxyl group-containing monomers, nitrogen atom-containing monomers, and epoxy group-containing monomers. , sulfonic acid group-containing monomers, phosphoric acid group-containing monomers, (meth)acrylic acid alkoxyalkyl esters, (meth)acrylic acid esters having aromatic hydrocarbon groups, vinyl esters, aromatic vinyl compounds, olefins, vinyl ethers , and vinyl chloride.

Styrenic monomers include, for example, styrene, ethylvinylbenzene, α-methylstyrene, vinyltoluene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, vinylbiphenyl and vinylnaphthalene.

Examples of carboxyl group-containing monomers include (meth)acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, isocrotonic acid, and acid anhydrides thereof (eg, maleic anhydride and itaconic anhydride).

Examples of (meth)acrylic acid alkyl esters include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, ( meth)isobutyl acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, isopentyl (meth)acrylate, hexyl (meth)acrylate, (meth)acrylic acid heptyl, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, (meth)acrylic Isodecyl acid, undecyl (meth)acrylate, dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, (meth)acrylic acid Heptadecyl, octadecyl (meth)acrylate, nonadecyl (meth)acrylate, eicosyl (meth)acrylate, cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, etc., having 1 to 1 carbon atoms (Meth)acrylic acid alkyl esters having 20 alkyl groups are mentioned. The alkyl group here includes an alicyclic hydrocarbon group and an alkyl group having an alicyclic hydrocarbon group. The alkyl group is an alkyl group having 1 to 8 carbon atoms in that the stability of the dispersion during suspension polymerization is excellent, and as a result, hollow porous resin particles with high mechanical strength are easily obtained. is preferred, and an alkyl group having 1 to 4 carbon atoms is more preferred.

Examples of hydroxyl group-containing monomers include hydroxyl group-containing (meth)acrylic acid esters, vinyl alcohol, and allyl alcohol. Examples of hydroxyl group-containing (meth)acrylic acid esters include 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 6-(meth)acrylate. Hydroxyhexyl, hydroxyoctyl (meth)acrylate, hydroxydecyl (meth)acrylate, hydroxyllauryl (meth)acrylate, and (4-hydroxymethylcyclohexyl) (meth)acrylate.

A nitrogen atom-containing monomer is a monomer having at least one nitrogen atom in the molecule. In this specification, a monomer having both a hydroxyl group and a nitrogen atom in the molecule is not included in the hydroxyl group-containing monomer, but is included in the nitrogen atom-containing monomer. Nitrogen atom-containing monomers include, for example, N-vinyl cyclic amides, (meth)acrylamides, amino group-containing monomers, cyano group-containing monomers, heterocyclic ring-containing monomers, imide group-containing monomers, and isocyanate group-containing monomers.

N-vinyl cyclic amides include, for example, N-vinyl-2-pyrrolidone (NVP), N-vinyl-2-piperidone, N-vinyl-3-morpholinone, N-vinyl-2-caprolactam, N-vinyl-1 ,3-oxazin-2-one, and N-vinyl-3,5-morpholinedione.

Examples of (meth)acrylamides include (meth)acrylamide, N-alkyl(meth)acrylamide, N,N-dialkyl(meth)acrylamide, N-hydroxyalkyl(meth)acrylamide, and N-alkoxyalkyl(meth)acrylamide. is mentioned.

Examples of N-alkyl(meth)acrylamides include N-ethyl(meth)acrylamide, N-isopropyl(meth)acrylamide, Nn-butyl(meth)acrylamide and N-octyl(meth)acrylamide. N-alkyl(meth)acrylamides also include (meth)acrylamides having an amino group, such as dimethylaminoethyl(meth)acrylamide, diethylaminoethyl(meth)acrylamide, and dimethylaminopropyl(meth)acrylamide.

N,N-dialkyl(meth)acrylamides include, for example, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N,N-dipropyl(meth)acrylamide, N,N-diisopropyl ( meth)acrylamide, N,N-di(n-butyl)(meth)acrylamide, N,N-di(t-butyl)(meth)acrylamide.

N-hydroxyalkyl(meth)acrylamides include, for example, N-methylol(meth)acrylamide, N-(2-hydroxyethyl)(meth)acrylamide, N-(2-hydroxypropyl)(meth)acrylamide, N-( 1-hydroxypropyl)(meth)acrylamide, N-(3-hydroxypropyl)(meth)acrylamide, N-(2-hydroxybutyl)(meth)acrylamide, N-(3-hydroxybutyl)(meth)acrylamide, N -(4-hydroxybutyl) (meth)acrylamide, N-methyl-N-2-hydroxyethyl (meth)acrylamide.

Examples of N-alkoxyalkyl(meth)acrylamides include N-methoxymethyl(meth)acrylamide and N-butoxymethyl(meth)acrylamide.

Examples of amino group-containing monomers include aminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, and t-butylaminoethyl (meth)acrylate.

Examples of cyano group-containing monomers include acrylonitrile and methacrylonitrile.

Examples of heterocyclic ring-containing monomers include (meth)acryloylmorpholine, N-vinylpiperazine, N-vinylpyrrole, N-vinylimidazole, N-vinylpyrazine, N-vinylmorpholine, N-vinylpyrazole, vinylpyridine, and vinylpyrimidine. , vinyloxazole, vinylisoxazole, vinylthiazole, vinylisothiazole, vinylpyridazine, (meth)acryloylpyrrolidone, (meth)acryloylpyrrolidine, (meth)acryloylpiperidine, N-methylvinylpyrrolidone.

Examples of imide group-containing monomers include maleimide monomers such as N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, and N-phenylmaleimide; N-methylitaconimide, N-ethylitaconimide, and N-butylitacon. Itaconimide-based monomers such as imide, N-octylitaconimide, N-2-ethylhexylitaconimide, N-laurylitaconimide, and N-cyclohexylitaconimide; N-(meth)acryloyloxymethylenesuccinimide, N-(meth)acryloyl- succinimide-based monomers such as 6-oxyhexamethylenesuccinimide and N-(meth)acryloyl-8-oxyoctamethylenesuccinimide;

Examples of isocyanate group-containing monomers include 2-(meth)acryloyloxyethyl isocyanate.

Examples of epoxy group-containing monomers include glycidyl (meth)acrylate and methylglycidyl (meth)acrylate.

Examples of sulfonic acid group-containing monomers include sodium vinyl sulfonate.

Examples of (meth)acrylic acid alkoxyalkyl esters include 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, and 3-(meth)acrylate. methoxypropyl, 3-ethoxypropyl (meth)acrylate, 4-methoxybutyl (meth)acrylate, and 4-ethoxybutyl (meth)acrylate.

(Meth)acrylic acid esters having an aromatic hydrocarbon group include, for example, phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, and benzyl (meth)acrylate.

Vinyl esters include, for example, vinyl acetate and vinyl propionate.

Examples of aromatic vinyl compounds include styrene and vinyl toluene.

Olefins include, for example, ethylene, butadiene, isoprene, and isobutylene.

Vinyl ethers include, for example, vinyl alkyl ethers.

Polyfunctional vinyl monomers having two or more ethylenically unsaturated groups include, for example, polyfunctional (meth)acrylate monomers and aromatic divinyl monomers.

Polyfunctional (meth)acrylic acid ester monomers include, for example, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, nonaethylene glycol di(meth)acrylate, tetradecaethylene glycol di(meth)acrylate, decaethylene glycol di(meth)acrylate, pentadecaethylene glycol di(meth)acrylate, 1,3-butylene glycol di(meth)acrylate, 1, 4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, glycerin di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, diethylene glycol phthalate di(meth)acrylates, caprolactone-modified dipentaerythritol hexa(meth)acrylates, caprolactone-modified hydroxypivalic acid ester neopentyl glycol di(meth)acrylates, polyester (meth)acrylates, and urethane (meth)acrylates.

Examples of aromatic divinyl-based monomers include divinylbenzene, divinylnaphthalene, and derivatives thereof.

The vinyl-based monomer preferably contains a polyfunctional vinyl-based monomer so that the effects of the present invention can be exhibited more effectively. The content of the polyfunctional vinyl-based monomer in the total amount of the vinyl-based monomer is preferably 3% to 70% by weight, more preferably 5% to 50% by weight, from the viewpoint that the effects of the present invention can be further expressed. , more preferably 7 wt % to 45 wt %, particularly preferably 10 wt % to 40 wt %. If the content of the polyfunctional vinyl-based monomer in the total amount of the vinyl-based monomer is too small outside the above range, it may become difficult to form a porous structure inside the particles. If the content of the polyfunctional vinyl-based monomer in the total amount of the vinyl-based monomer is too large outside the above range, the hollow porous resin particles obtained may have a large surface shrinkage and a weak mechanical strength.

The structural unit (II) derived from a phosphate ester-based monomer is a structural unit formed when the phosphate ester-based monomer is polymerized as one of all the monomer components used to produce the polymer (P2). is. As such a phosphate ester-based monomer, any appropriate phosphate ester-based monomer can be employed as long as the effects of the present invention are not impaired. Only one kind of phosphate monomer may be used, or two or more kinds thereof may be used.

The phosphate ester-based monomer preferably has an ethylenically unsaturated group because it can be copolymerized with the vinyl-based monomer in the vicinity of the surface of the droplet during suspension polymerization to increase the particle hardness.

As the phosphate ester-based monomer, during suspension polymerization, the acidic phosphate ester-based monomer is easily oriented on the droplet surface, acts with the inorganic dispersant, and can increase the hardness near the particle surface. preferable.

As the acidic phosphate monomer having an ethylenically unsaturated group, the phosphate ester monomer represented by the general formula (1) is preferable in that the effects of the present invention can be exhibited more effectively.

In general formula (1), R ¹ is a (meth)acryl group or allyl group, R ² is a linear or branched alkylene group, m is an integer of 1 to 30, n is 0 or 1, v is 1 to An integer of 10, x is 1 or 2.

From the viewpoint that the effect of the present invention can be more expressed, the phosphate monomer represented by the general formula (1) includes a caprolactone EO-modified phosphate dimethacrylate represented by the formula (2), Polyoxypropylene allyl ether phosphate and 2-methacryloyloxyethyl acid phosphate represented are preferred.

In formula (2), a and b are a=1 and b=2, or a=2 and b=1.

In formula (3), p is an integer of 1-30. q is 1 or 2;

The caprolactone EO-modified phosphate dimethacrylate represented by formula (2) is available, for example, under the product name “KAYAMER PM-21” from Nippon Kayaku Co., Ltd.

The polyoxypropylene allyl ether phosphate represented by the formula (3) is available, for example, from ADEKA Corporation under the product name "Adekari Soap PP-70".

In the hollow porous resin particles, the polymer (P2), which is the main component thereof, is a polymer containing both the structural unit (I) derived from the vinyl-based monomer and the structural unit (II) derived from the phosphate ester-based monomer. In some cases, the content of the phosphate ester-based monomer in all the monomer components used for producing the polymer is preferably 0.001 to 5 parts by weight with respect to 100 parts by weight of the vinyl-based monomer. 0.01 to 3 parts by weight, more preferably 0.03 to 1 part by weight, and particularly preferably 0.05 to 0.8 parts by weight. If the content of the phosphate ester-based monomer is within the above range with respect to 100 parts by weight of the vinyl-based monomer, the effects of the present invention can be exhibited more effectively.

The hollow porous resin particles include a polymer (P2) containing at least one selected from the group consisting of vinyl-based monomer-derived structural units (I) and phosphoric acid ester-based monomer-derived structural units (II). , may contain any appropriate other component within a range that does not impair the effects of the present invention. Only one such component may be used, or two or more components may be used. Such other ingredients include, for example, pigments, antioxidants, perfumes, UV protection agents, surfactants, preservatives, and medicinal ingredients.

Hollow porous resin particles can be produced, for example, by a production method including a dispersing step, a polymerization step, a washing step, and a drying step.

[Dispersion step]
In the dispersing step, an organic mixed solution containing a monomer component containing at least one selected from the group consisting of vinyl-based monomers and phosphate ester-based monomers, a polymerization initiator, and a non-polymerizable organic compound is added to an aqueous solution containing a dispersant. This is a dispersing step. The dispersing method is as described for the production of the superficially porous resin particles.

Aqueous solutions include an aqueous medium and a dispersing agent.

The aqueous medium is as described for the production of superficially porous resin particles.

As the dispersant, any appropriate dispersant can be employed as long as the effects of the present invention are not impaired. Examples of such dispersants include inorganic dispersants and surfactants. An inorganic dispersant is preferably employed as the dispersant in that the effects of the present invention can be exhibited more effectively. Only one dispersant may be used, or two or more dispersants may be used.

Examples of inorganic dispersants include alkaline earth metal pyrophosphates (magnesium pyrophosphate, etc.), alkaline earth metal phosphates (tertiary calcium phosphate, etc.), calcium carbonate, barium carbonate, etc., which are sparingly soluble in water. inorganic dispersants such as silica and zirconium oxide; inorganic polymeric substances such as talc, bentonite, silicic acid, diatomaceous earth and clay; The alkaline earth metals referred to here are preferably magnesium and calcium. Among these, alkaline earth metal pyrophosphates and alkaline earth metal phosphates form a dense coating on the surface layer by interaction of metal ions with the phosphoric acid ester moiety in the phosphoric acid ester-based monomer. As a result, it is preferable in that hollow porous resin particles having high mechanical strength can be obtained.

The amount of the inorganic dispersant to be added is preferably 0.00% per 100 parts by weight of the monomer component in order to ensure the stability of the oil droplets and to obtain hollow porous resin particles having a uniform particle size. It is 1 to 30 parts by weight, more preferably 0.5 to 20 parts by weight.

Examples of surfactants include anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants. Specific examples of surfactants are as described for the production of superficially porous resin particles.

The amount of the surfactant to be added is preferably 0.01 to 1 part by weight with respect to 100 parts by weight of the organic mixed solution. Only one type of surfactant may be used, or two or more types may be used.

The aqueous solution may contain any appropriate other component as long as the effects of the present invention are not impaired.

The organic mixed solution contains a monomer component including at least one selected from the group consisting of vinyl-based monomers and phosphate-based monomers, a polymerization initiator, and a non-polymerizable organic compound.

The monomer components contained in the organic mixed solution are as described above.

As the polymerization initiator, any appropriate polymerization initiator can be employed as long as the effects of the present invention are not impaired. Specific examples of the polymerization initiator are as described for the production of the superficially porous resin particles.

The amount of the polymerization initiator to be added is preferably 0.01 to 10 parts by weight, more preferably 0.01 to 5 parts by weight, and still more preferably 0 parts by weight with respect to 100 parts by weight of the monomer component. .1 to 5 parts by weight. Only one polymerization initiator may be used, or two or more polymerization initiators may be used.

The non-polymerizable organic compound functions as a so-called solvent and also contributes to the formation of a porous structure inside the resin particles.

As such a non-polymerizable organic compound, it is preferable to use an organic solvent having a boiling point of 30° C. or more and 200° C. or less because it exists as a liquid in the temperature range where the polymerization step is performed. More specifically, non-polymerizable organic compounds include saturated aliphatic hydrocarbons such as n-pentane, isopentane, n-hexane, cyclohexane and n-heptane; aromatic compounds such as toluene and benzene; ethyl acetate , butyl acetate, and other acetic acid ester compounds; hydrofluoroethers, hydrofluorocarbons, and other fluorine compounds;

The amount of the non-polymerizable organic compound used is preferably 10 parts by weight to 250 parts by weight with respect to 100 parts by weight of the monomer component, in order to exhibit the effects of the present invention. If the amount of the non-polymerizable organic compound used relative to 100 parts by weight of the monomer component is too small outside the above range, there is a risk that a porous structure cannot be reliably formed inside the resin particles. If the amount of the non-polymerizable organic compound used relative to 100 parts by weight of the monomer component is out of the above range and is too large, there is a risk that sufficient strength cannot be imparted to the obtained hollow porous resin particles.

The organic mixed solution may contain any appropriate other component within a range that does not impair the effects of the present invention.

[Polymerization step]
The polymerization step is a step of heating the dispersion obtained in the dispersion step to carry out suspension polymerization.

Any appropriate polymerization temperature can be adopted as long as the polymerization temperature is suitable for suspension polymerization, as long as the effects of the present invention are not impaired. Such a polymerization temperature is preferably 30°C to 105°C.

As long as the polymerization time is suitable for suspension polymerization, any suitable polymerization time can be adopted as long as the effects of the present invention are not impaired. Such polymerization time is preferably 0.1 hour to 20 hours.

Post-heating, which is preferably performed after polymerization, is a suitable treatment for obtaining hollow porous resin particles with a high degree of perfection.

Any appropriate temperature can be adopted as the temperature of the post-heating that is preferably performed after the polymerization, as long as the effects of the present invention are not impaired. The temperature for such post-heating is preferably 50°C to 120°C.

Any suitable time can be adopted as the post-heating time, which is preferably performed after polymerization, as long as the effects of the present invention are not impaired. The time for such post-heating is preferably 1 hour to 10 hours.

[Washing process]
The washing step is a step of washing the slurry obtained in the polymerization step.

Any suitable cleaning method may be employed as long as the effects of the present invention are not impaired. As such a washing method, for example, (1) after forming hollow porous resin particles, a high-speed centrifuge or the like is used to apply a very high centrifugal acceleration to sediment the hollow porous resin particles. remove the supernatant, add fresh ion-exchanged water or distilled water, disperse the precipitated hollow porous resin particles in the ion-exchanged water, and repeat this operation several times to remove impurities, (2 ) A method of removing impurities by washing by a cross-flow filtration method using a ceramic filter or the like; and a method in which particles are aggregated and sedimented in a solvent, the hollow porous resin particles are separated using a filter or the like, and washed with a washing solvent.

In the cleaning method (1) above, it is preferable to use ion-exchanged water or distilled water in an amount of 5 times or more the weight of the slurry.

For hollow porous resin particles with a small specific gravity, it is preferable to wash them by a cross-flow filtration method using a ceramics filter or the like of (2).

[Drying process]
The drying step is a step of drying the washed slurry obtained in the washing step.

Any appropriate drying method may be employed as long as the effects of the present invention are not impaired. Such a drying method includes, for example, drying by heating.

Any appropriate temperature can be adopted as the heating temperature as long as the effects of the present invention are not impaired. The temperature for such heating is preferably 50°C to 120°C.

Any appropriate heating time can be adopted as long as the effects of the present invention are not impaired. Such heating time is preferably 1 hour to 50 hours.

C. Other Components As other components, any appropriate component can be used as long as the effects of the present invention can be obtained. For example, flame retardants, fluidity improvers, heat stabilizers, antioxidants, colorants, release agents, softeners, antistatic agents, impact modifiers and the like can be used. Also, a resin other than the base resin (A) may be used.

Examples of flame retardants include organic metal salt flame retardants (e.g., alkali (earth) metal salts of organic sulfonates, metal borate flame retardants, and metal stannate flame retardants), and organic phosphorus flame retardants. (For example, monophosphate compounds, phosphate oligomer compounds, phosphonate oligomer compounds, phosphonitrile oligomer compounds, phosphonic acid amide compounds, etc.), silicone-based flame retardants made of silicone compounds, and the like.

Fluidity improvers include, for example, copolymers of aromatic vinyl monomers and phenyl methacrylate. Examples of aromatic vinyl monomers include styrene, α-methylstyrene, p-tert. Butylstyrene and the like can be mentioned, and these can be used alone or in combination of two or more. Preferred fluidity improvers include styrene/phenyl methacrylate copolymers or styrene/α-methylstyrene/phenyl methacrylate copolymers.

Examples of heat stabilizers include pentaerythritol tetrakis [3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5-di-tert-butyl-4- hydroxyphenyl) propionate and other phenolic heat stabilizers, tris(2,4-di-tert-butylphenyl)phosphite and other phosphorus heat stabilizers, 3-hydroxy-5,7-di-tert-butyl-furan Lactone-based heat stabilizers such as reaction products of -2-one and o-xylene, and sulfur-based heat stabilizers such as didodecyl-3,3'-thiodipropionate.

As the antioxidant, those described in the above section B-1 can be used.

Examples of coloring agents include titanium oxide, carbon black, titanium yellow, iron oxide, ultramarine blue, cobalt blue, baked pigments, metallic pigments, mica, pearl pigments, zinc white, precipitated silica, cadmium red, and the like.

Fatty acid esters, for example, are preferred as release agents. Specific examples of fatty acid esters include behenyl behenate, octyldodecyl behenate, stearyl stearate, glycerin monopalmitate, glycerin monostearate, glycerin monooleate, glycerin distearate, glycerin tristearate, penta erythritol monopalmitate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, pentaerythritol tetrastearate and the like.

Examples of softening agents include process oil, lubricating oil, paraffin, liquid paraffin, petroleum asphalt, petroleum softening agents such as vaseline, coal tar softening agents such as coal tar and coal tar pitch, castor oil, rapeseed oil, and Fatty oil-based softeners such as soybean oil and coconut oil, tall oil, beeswax, carnauba wax, lanolin and other waxes, ricinoleic acid, palmitic acid, stearic acid, barium stearate, calcium stearate and other fatty acids or metal salts thereof, naphthene Acid or its metallic soap, pine oil, rosin or its derivative, terpene resin, petroleum resin, coumarone-indene resin, synthetic polymer substances such as atactic polypropylene, ester plasticizers such as dioctyl phthalate, dioctyl adipate, dioctyl sebacate , carbonate plasticizers such as diisododecyl carbonate, microcrystalline wax, sub (factice), liquid polybutadiene, modified liquid polybutadiene, liquid thiocol, and hydrocarbon synthetic lubricating oils.

Antistatic agents include, for example, polyoxyethylene alkylphenol ether, stearic acid monoglyceride, polyethylene glycol, carbon nanotubes, and the like.

Examples of impact modifiers include acrylic rubbers, styrene/hydrogenated butadiene/styrene block copolymers, styrene/hydrogenated isoprene/styrene block copolymers, AES resins, AAS resins, polybutadiene, butadiene/styrene copolymers. Polymers, polyisoprene, etc., preferably acrylic rubber, styrene/hydrogenated butadiene/styrene block copolymer, styrene/hydrogenated isoprene/styrene block copolymer, AES resin, AAS resin, Acrylic rubber is more preferred. Acrylic rubbers include, for example, multi-layered polymers containing alkyl (meth)acrylate (collective term for alkyl acrylate and alkyl methacrylate, hereinafter the same) polymer. Specifically, there is a multi-layer structure polymer composed of a core made of a saturated or unsaturated rubber component and a shell made of an alkyl (meth)acrylate polymer. By using an acrylic rubber, especially a multi-layer structure polymer, it is easy to obtain a resin composition excellent in impact strength and molded product appearance. Examples of saturated or unsaturated rubber components forming the core include polyalkyl (meth)acrylates, polybutadiene, butadiene/styrene copolymers, and the like. Examples of the alkyl (meth)acrylate polymer that forms the shell include alkyl (meth)acrylates having an alkyl group having about 1 to 8 carbon atoms, such as ethyl (meth)acrylate, butyl (meth)acrylate, and ethylhexyl (meth)acrylate. Examples include polymers or copolymers such as acrylates. The alkyl (meth)acrylate polymer may contain a cross-linking agent such as an ethylenically unsaturated monomer. Examples of cross-linking agents include alkylenediol di(meth)acrylate, polyester di(meth) acrylates, divinylbenzene, trivinylbenzene, triallyl cyanurate, allyl (meth)acrylate and the like.

The content of other components (the total content when multiple components are included) is, for example, 0.01 to 20 parts by weight, preferably 0, with respect to 100 parts by weight of the base resin (A). .1 to 10 parts by weight.

D. Method for producing resin composition The resin composition comprises 15 to 99 parts by weight of the base resin (A), 0.01 to 20 parts by weight of the porous resin particles (B), and optionally other Obtained by mixing the components

Examples of the mixing method include a method of mixing using a known mixer such as a tumbler and a ribbon blender, and a method of melt-kneading with an extruder. Pellets of the resin composition can be easily obtained by these mixing methods.

≪Molded body≫
A molded article according to an embodiment of the present invention includes the above resin composition. Any appropriate molding method can be used depending on the purpose. For example, a molded article having an arbitrary shape can be obtained by extruding pellets of the resin composition, or by injection molding after melting the pellets.

The molded article may be, for example, a housing for vehicle equipment, a housing for electrical equipment, a housing for electronic equipment, a housing for IT equipment, a housing for measuring equipment, or an automobile interior or exterior member.

EXAMPLES The present invention will be specifically described below with reference to Examples, but the present invention is not limited to these Examples. "Parts" means "parts by weight" and "%" means "% by weight" unless otherwise specified.

<Measurement of volume average particle size>
The volume average particle diameter of particles was measured by the Coulter method as follows.
The volume-average particle size of the particles was measured with a Coulter Multisizer (registered trademark) 3 (measurement device manufactured by Beckman Coulter, Inc.). Measurements were performed with an aperture calibrated according to the Multisizer® 3 User's Manual published by Beckman Coulter, Inc. The aperture used for measurement was appropriately selected depending on the size of the particles to be measured. Current (aperture current) and Gain (gain) were appropriately set according to the size of the selected aperture. For example, when an aperture with a size of 50 μm was selected, Current (aperture current) was set to −800 and Gain was set to 4.
As a sample for measurement, 0.1 g of particles was added to 10 ml of a 0.1% by weight nonionic surfactant aqueous solution using a touch mixer (“TOUCHMIXER MT-31” from Yamato Scientific Co., Ltd.) and an ultrasonic cleaner (Velvok Co., Ltd.). Leah, "ULTRASONIC CLEANER VS-150") was used to obtain a dispersion liquid. During the measurement, the inside of the beaker was gently stirred to the extent that air bubbles were not introduced, and the measurement was terminated when 100,000 particles were measured. The volume average particle diameter of the particles was the arithmetic mean of the volume-based particle size distribution of 100,000 particles.

<Bulk specific gravity>
The bulk specific gravity of the particles was measured according to JISK5101-12-1 (Pigment test method-Part 12: Apparent density or apparent specific volume-Section 1: Static method).

<Specific surface area>
The specific surface area of the particles was measured by the BET method (nitrogen adsorption method) described in ISO 9277 1st edition JIS Z 8830:2001. For the target particles, the BET nitrogen adsorption isotherm is measured using an automatic specific surface area / pore distribution measuring device "Tristar II" manufactured by Shimadzu Corporation, and the specific surface area is calculated from the nitrogen adsorption amount using the BET multipoint method. Calculated.
After pretreatment by hot gas purging, nitrogen was used as the adsorbate, and the measurement was performed using the constant volume method under the conditions of the adsorbate cross-sectional area of 0.162 nm ² . Specifically, the pretreatment is performed by nitrogen purging for 20 minutes while heating the container containing the particles at 65 ° C., allowing to cool to room temperature, and then heating the container at 65 ° C., This was done by vacuum degassing until the pressure was less than 0.05 mmHg.

<Thermal decomposition initiation temperature>
The thermal decomposition start temperature of the particles is 20 in the range of 40 ° C. to 100 ° C. in an air atmosphere at an air flow rate of 200 ml / min using a TG / DTA device (“TG / DTA6200” manufactured by Seiko Instruments Inc.). The weight loss behavior was measured in the range of 40°C to 500°C under the measurement conditions of a temperature increase rate of °C/min and a temperature increase rate of 10°C/min in the range of 100°C to 500°C. The intersection of the extension of the base line (horizontal line) of the weight loss curve obtained by this measurement and the tangent line (tangent line at the point of maximum inclination) of the mass decrease portion (slanted line portion downward to the right) is the thermal decomposition of the resin particles. was taken as the starting temperature.

<Measurement of Melt Volume Flow Rate (MVR)>
The MVR of the resin compositions (pellets) obtained in Examples and Comparative Examples was measured using a "melt flow index tester (automatic) 120-SAS" manufactured by Yasuda Seiki Seisakusho Co., Ltd., according to JIS K 7210: 1999 "Plastics - Thermal Melt mass flow rate (MFR) and melt volume flow rate (MVR) of plastic plastic were measured by the method of measuring the time required for the piston to move a predetermined distance described in B Method b. The pellets were previously vacuum-dried at 120° C. for 6 hours, then sealed and stored until just before the measurement.
Specifically, it was measured under the following conditions.
・Preheat: 300 seconds ・Load hold: 30 seconds ・Test temperature: 250°C
・Test load: 2.16 kg (21.18 N)
・Piston movement distance (interval): 25mm
The sample was tested three times, and the average was taken as the value of MVR (cm ³ /10 min).

<Measurement of total light transmittance and haze>
The resin compositions (pellets) obtained in Examples and Comparative Examples were hot-pressed at 210° C. for 5 minutes to obtain plate-shaped moldings with a thickness of 1 mm. A test piece obtained by cutting the plate-shaped compact into a length of 50 mm and a width of 40 mm was used.
The total light transmittance and haze were measured using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., trade name "NDH4000"). Total light transmittance was measured according to JIS K7361-1, and haze was measured according to JIS K7136. Two test pieces were measured, and the average value of the obtained two measured values was used as the final measured value.

<Tensile stress relaxation test>
Using the resin composition (pellet) obtained in Examples and Comparative Examples and the base resin, a plate-shaped molding having a thickness of 1 mm was produced in the same manner as the test piece for total light transmittance. A dumbbell shape (dumbbell shape No. 5 according to JIS K7127: width 6 mm, thickness 1 mm) was used as a test piece.
The tensile stress relaxation test was performed using a universal testing machine manufactured by Shimadzu Corporation "Autograph AG-X plus 100 kN" and a universal testing machine manufactured by Shimadzu Corporation "TRAPEZIUM-X" for data processing. The test piece was used for measurement after being conditioned for 16 hours in a standard atmosphere of JIS K 7100:1999, "23/50", Class 2. The measurements were carried out under the same environment, specifically under the following conditions.
・Chuck interval: 80mm
- Test method: A test speed was set to 10 mm/min, and the test was started after deflection correction.
- After the start of the test, when the strain of the test piece reached 1.5%, the movement of the gripper was stopped, and the test piece was kept as it was for 5 minutes. The strain of the test piece was measured by the amount of crosshead movement.
・Number of tests: 5
The stress relaxation rate R was calculated from the following formula.
R(%)=(σ0−σ5)/σ0×100
Here, σ0 represents the tensile stress of the test piece when a tensile strain of 1.5% is applied to the test piece, and σ5 is the time from when the 1.5% tensile strain was applied to the test piece. It represents the tensile stress of the specimen after 5 minutes.

<Tensile strength and tensile modulus>
Tensile strength and tensile modulus were measured according to JIS K7127:1999. The tensile strength and tensile elastic modulus were measured using a universal testing machine "Autograph AG-X plus 100 kN" manufactured by Shimadzu Corporation and a universal testing machine "TRAPEZIUM X" manufactured by Shimadzu Corporation for data processing. The test piece was prepared by punching out a plate-shaped molded body prepared in the same manner as the test piece for total light transmittance into a dumbbell shape (dumbbell shape No. 5 according to JIS K7127: width 6 mm, thickness 1 mm). was used. The test piece was used for measurement after being conditioned for 16 hours in a standard atmosphere of JIS K 7100:1999, "23/50", Class 2. The measurement was performed under the same environment, with the chuck interval set at 80 mm and the test speed set at 10 mm/min. From the obtained graph, a load region with the maximum slope was set, and the apparent tensile elastic modulus was determined by the universal testing machine data processing. The intersection point of the straight line of the elastic modulus and the stroke was taken as the origin of elongation, and the tensile strength and the tensile elastic modulus were automatically calculated.

<Bending strength and bending elastic modulus>
Bending strength and bending elastic modulus were measured according to JIS K7171:2008. The flexural strength and flexural modulus were measured using an "Autograph AG-X plus 100 kN" universal testing machine manufactured by Shimadzu Corporation and a "TRAPEZIUM X" universal testing machine manufactured by Shimadzu Corporation for data processing. A test piece was prepared by injection molding at a cylinder temperature of 260°C and a mold temperature of 70°C. The size of the test piece was 10 mm in width×80 mm in length×4 mm in thickness, and the number of test pieces was 5. The test piece was used for the measurement after conditioning for 16 hours in a standard atmosphere of JIS K7100:1999 "23/50", Class 2. Measurement was performed under the same environment, and the test speed was 2 mm/min. The radius of the tip of the pressure wedge and the fulcrum was 5R, and the distance between the fulcrums was 64 mm.
From the obtained graph, the load region where the slope becomes maximum was set, and the flexural modulus was obtained by the universal testing machine data processing described above. Using the elongation at the intersection of the straight line of the elastic modulus and the stroke as the origin, the corresponding maximum bending strength was automatically calculated.

<Measurement of deflection temperature under load (HDT)>
The resin compositions (pellets) obtained in Examples and Comparative Examples were molded into test pieces having a thickness of 4 mm based on ISO75-2 under conditions of a cylinder temperature of 260°C and a mold temperature of 70°C. Using the obtained test piece, the deflection temperature under load (1.80 MPa load) was measured according to ISO75-2.

[Production Example 1: Production of surface porous resin particles (B1)]
To 1000 g of deionized water, 50 g of tribasic calcium phosphate as an inorganic dispersant and 0.05 g of sodium lauryl sulfate as an anionic surfactant were added to prepare an aqueous phase. On the other hand, 160 g of methyl methacrylate (MMA), 240 g of ethylene glycol dimethacrylate (EGDMA), 4 g of pentaerythritol tetrakisthioglycolate as an antioxidant, 700 g of ethyl acetate as a non-polymerizable organic compound, and a polymerization initiator. A mixed solution with 1 g of lauroyl peroxide was prepared as an oil phase. The aqueous phase and the oil phase were mixed and dispersed for 5 minutes at 6000 rpm with a TK-Homomixer (manufactured by Primix) to obtain a dispersion having a volume average particle size of approximately 8 μm. This dispersion was placed in a polymerization vessel equipped with a stirrer and a thermometer, and heated to 70° C. under stirring and nitrogen replacement to initiate suspension polymerization. By maintaining the internal temperature at 70° C. for 8 hours, a suspension containing resin particles was obtained (polymerization step).
The suspension containing the resin particles was distilled under conditions of 80° C. and 0.027 MPa to remove ethyl acetate out of the system (distillation step).
After cooling the suspension to 20° C. and adding hydrochloric acid to decompose the tribasic calcium phosphate, the resin particles obtained were separated by filtration using a Buchner funnel, and then the resin particles were washed with ion-exchanged water ( decomposition removal step).
The washed resin particles were dried at 90° C. under reduced pressure of 0.008 MPa for 24 hours to obtain resin particles (drying step).

The volume average particle diameter of the resin particles was 8.0 μm. As shown in FIG. 1, SEM observation of the resin particle surface revealed that the surface had a porous shape. Further, as shown in FIG. 2, after the resin particles were embedded in the epoxy resin, they were cut into thin slices, and the cross section of the particles was observed with an SEM. was done. Moreover, the specific surface area of the resin particles was 170 m ² /g. The thermal decomposition initiation temperature was 292°C.

[Production Example 2: Production of hollow porous resin particles (B2)]
65 parts by weight of methyl methacrylate (MMA), 85 parts by weight of ethylene glycol dimethacrylate, and 0.3 parts by weight of a polymerizable monomer having an acidic phosphate group "KAYAMER (registered trademark) PM-21" (manufactured by Nippon Kayaku Co., Ltd.) , 2,2'-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator (manufactured by Nippon Finechem Co., Ltd., trade name "ABN-V", 10-hour half-life temperature = 51 ° C.) 0.75 parts by weight, An oil phase was prepared by mixing 75 parts by weight of ethyl acetate as a non-polymerizable organic compound and 75 parts by weight of cyclohexane. An aqueous phase was prepared by mixing 900 parts by weight of deionized water as an aqueous medium and 90 parts by weight of tribasic calcium phosphate as a dispersant. Next, the oil phase was dispersed in the aqueous phase at 8000 rpm for 5 minutes using TK-Homomixer (manufactured by Primix) to obtain a dispersion having a volume average particle size of approximately 8 μm (dispersion step).
After that, the dispersion liquid was put into a polymerization vessel equipped with a stirrer and a thermometer, the internal temperature of the polymerization vessel was raised to 55°C, and the suspension was continuously stirred for 5 hours. was heated to 70°C (secondary temperature rise), and the suspension was stirred at 70°C for 7 hours to complete the suspension polymerization reaction (polymerization step).
After cooling the suspension, the dispersing agent (magnesium pyrophosphate) contained in the suspension was decomposed with hydrochloric acid. Thereafter, using a centrifugal filter, the suspension was dehydrated by filtration to separate the solid content, and the solid content was washed with sufficient ion-exchanged water (washing step).
After that, the non-polymerizable organic compound was removed by vacuum drying at 70° C. for 24 hours to obtain spherical resin particles (drying step).

The volume average particle diameter of the resin particles was 8.0 μm. As shown in FIG. 3, SEM observation of the resin particle surface revealed that the particle surface was a dense shell with no pores. Further, as shown in FIG. 4, when the resin particles were embedded in the epoxy resin and then cut into thin film slices and the cross sections of the particles were observed with an SEM, it was confirmed that the inside of the particles had a porous structure. The resin particles had a specific surface area of 7.2 m ² /g and a bulk specific gravity of 0.32 g/cm ³ .

Raw materials used in Examples and Comparative Examples are as follows.
・ Polycarbonate resin: “SD Polyca 301-22 (trade name)” manufactured by Sumika Polycarbonate Co., Ltd.
・PC/ABS alloy resin: “SD Polyca IM6120 (trade name)” manufactured by Sumika Polycarbonate Co., Ltd.
・PC/PET alloy resin: “Taflon SC-420 (trade name)” manufactured by Idemitsu Kosan Co., Ltd.
・PC/PBT alloy resin: “SD Polyca CR3420T (trade name)” manufactured by Sumika Polycarbonate Co., Ltd.
・PBT resin: “DURANEX 500FP (trade name)” manufactured by Polyplastics
・Surface porous resin particles (B1): Particles obtained in Production Example 1 ・Hollow porous resin particles (B2): Particles obtained in Production Example 2 ・Spherical solid resin particles: Acrylic spherical solid Resin particles ("MBX-8" manufactured by Sekisui Plastics Co., Ltd., volume average particle diameter 8 μm)
· Phosphorus antioxidant: tris (2,4-di-t-butylphenyl) phosphite ("Irgafos 168" manufactured by BASF)

[Examples 1 to 19 and Comparative Examples 1 to 4]
Each raw material is put into a tumbler at once at the blending ratio shown in Tables 1 to 3, dry-mixed for 10 minutes, and then kneaded at a melting temperature of 260 ° C. using a twin-screw extruder to form pellets of the resin composition. Obtained.

Tables 1 to 3 show various evaluation results of the obtained resin compositions or molded articles thereof.

As shown in Tables 1 to 3, the resin compositions of Examples containing porous resin particles have improved stress relaxation properties and excellent light diffusion properties while maintaining a high MVR.

INDUSTRIAL APPLICABILITY According to the resin composition according to the embodiment of the present invention, it is possible to provide a highly designed molded article having excellent stress relaxation properties and light diffusing properties. Therefore, the resin composition and molded article according to the embodiments of the present invention can be It can be applied to an exterior member.

Claims (11)

Selected from the group consisting of polycarbonate resins, vinyl copolymers containing structural units derived from aromatic vinyl monomers and structural units derived from vinyl cyanide monomers, polyester resins, styrene resins, and (meth)acrylic resins 15 parts by weight to 99 parts by weight of the base resin (A) made of at least one thermoplastic resin,
0.01 to 20 parts by weight of the porous resin particles (B);
A resin composition containing In a tensile stress relaxation test, the stress relaxation rate R1 of the resin composition and the stress relaxation rate R0 of the base resin (A) satisfy the following formula (1),
0.3%≦R1−R0≦5.0% (1)
In the tensile stress relaxation test, a tensile force is applied to the test piece (width: 6 mm, thickness: 1 mm, test piece shape: dumbbell-shaped No. 5 according to JIS K7127), 1.5% tensile strain is applied, A test in which the tensile strain is maintained for 5 minutes after the 1.5% tensile strain is applied,
The stress relaxation rate R is expressed by the following formula (2):
R(%)=(σ0−σ5)/σ0×100 (2)
where σ0 represents the tensile stress of the test piece when the 1.5% tensile strain is applied to the test piece, and σ5 is the 1.5% tensile strain applied to the test piece. The resin composition according to claim 1, which represents the tensile stress of the test piece 5 minutes after the tensile strain was applied. 2. The resin composition according to claim 1, wherein the porous resin particles (B) have a volume average particle size of 1 μm to 50 μm. The porous resin particles (B) are surface porous resin particles (B1) having a porous surface and a porous interior, and hollow porous resin particles having a non-porous surface and a porous interior. The resin composition according to claim 1, comprising at least one selected from particles (B2). 5. The resin composition according to claim 4, wherein the surface porous resin particles (B1) have a specific surface area of 70 m ² /g to 300 m ² /g. The surface porous resin particles (B1) contain a polymer containing a structural unit derived from methyl methacrylate and a structural unit derived from a (meth)acrylic crosslinkable monomer,
The content ratio of the structural unit derived from methyl methacrylate in the total amount of structural units constituting the polymer is 1% by weight to 50% by weight,
5. The resin composition according to claim 4, wherein the content of structural units derived from the (meth)acrylic crosslinkable monomer in the total amount of structural units constituting the polymer is 50% by weight to 99% by weight. 5. The hollow porous resin particles (B2) according to claim 4, wherein the hollow porous resin particles (B2) have a specific surface area of 1 m ² /g to 30 m ² /g and a bulk specific gravity of 0.01 g/cm ³ to 0.6 g/cm ³ . of the resin composition. A polymer in which the hollow porous resin particles (B2) contain at least one selected from the group consisting of a structural unit derived from a vinyl monomer and a structural unit derived from a phosphoric acid ester monomer having an ethylenically unsaturated group. The resin composition according to claim 4, comprising It further contains at least one selected from the group consisting of flame retardants, fluidity improvers, heat stabilizers, antioxidants, colorants, release agents, softeners, antistatic agents, and impact modifiers. , The resin composition of claim 1. A molded article comprising the resin composition according to any one of claims 1 to 9. 11. The molded product according to claim 10, which is a housing for vehicle equipment, a housing for electrical equipment, a housing for electronic equipment, a housing for IT equipment, a housing for measuring equipment, or an automobile interior and exterior member.

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